Vivian is African-American, with Irish genetics as well, and is very pale but with a dark coloring. She makes Anita think of a delicate beautiful doll and feel protective of her. Anita believes she is the most beautiful woman she has ever met, perfect in proportion with brown eyes. Anita meets her when the Vampire Council comes to St. Louis and The Master of Beasts takes over the wereleopards and makes Vivian his pet, promising her riches for the injuries she can survive. Throughout the mid and later novels, Vivian has been dating Stephen, a werewolf and Gregory's twin.
In Kiss the Dead, Stephen is no longer dating Vivian but rather "Vanessa," which is probably just a continuity error about her name rather than a different person.